New Delhi — The Indian Institute of Technology Delhi (IIT Delhi), in collaboration with SJVN Limited, has successfully completed a 30-month research and development project on “High-Performance Concrete (HPC) for Sluice Spillways of Dams and Barrages.” The project was led by Prof. Sahil Bansal, Department of Civil and Environmental Engineering, IIT Delhi, with the objective of finding durable solutions to frequent and costly repairs in hydraulic structures.

The Nathpa Jhakri Hydropower Project, India’s largest hydropower plant with a capacity of 1,500 MW, has been facing recurring damage in its sluice spillways due to highly silt-laden flows, boulder impacts, and extreme hydraulic conditions. These severe erosion forces cause crushing, cracking, and surface wear of concrete, leading to annual repair needs and increased maintenance expenditure. Traditional repair approaches using conventional concrete have shown limited effectiveness in resisting such harsh conditions.

To address this challenge, IIT Delhi researchers developed and tested High-Performance Concrete (HPC) and Ultra-High-Performance Concrete (UHPC) mixes with enhanced abrasion resistance, impact resistance, and energy absorption capacity. Laboratory investigations demonstrated that these concretes not only provide higher compressive and flexural strength but also show significantly reduced material loss under underwater abrasion and hydraulic impact testing. Incorporation of supplementary cementitious materials and steel fibers further improved performance.

The research team implemented these mixes in field trials at Nathpa Dam in 2024 and 2025, carrying out repairs in multiple sluice bays. The approach involved reinstating steel rails, as per the original design, to counter boulder impacts, and applying HPC and UHPC to protect the rails and base concrete. Inspections confirmed that this method withstood harsh monsoon flows more effectively than conventional repair materials. The results demonstrate that combining steel rails with HPC/UHPC can significantly extend the service life of spillways, optimize repair cycles, and reduce long-term operational costs.

The study has delivered practical guidelines for the preparation, placement, and quality control of HPC for dam repair projects, including mix proportioning, site acceptance criteria, and recommended repair methodologies. These outcomes are expected to benefit hydropower operators across India and beyond, providing a reliable framework for enhancing the durability and resilience of critical water infrastructure.

This successful collaboration between IIT Delhi and SJVN Limited marks a step forward in applied research for infrastructure resilience and underscores the importance of academia-industry partnerships in addressing real-world engineering challenges.

                                                           SJVN Ltd and IIT Delhi joint visit to Nathpa Dam, 2023.